package _func

import "fmt"

func eval(a,b int,op string) int {
	switch op {
	case "+":
		return a+b
	case "-":
		return a-b
	case "*":
		return a*b
	case "/":
		q,_ :=div(a,b)
		return q
	default:
		panic("unsupported operation:"+op)
	}
}

func div(a,b int)(q,r int)  {

	return a/b,a%b
}

func swap(a , b int) (int, int) {
	return b,a
}


func main() {
	fmt.Println(eval(3,4,"/"))
	q,r:= div(13,3)
	fmt.Println(q,r)
	fmt.Println(swap(3,4))
}
